• Atmosphere
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• v.17 no.3
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• pp.241-253
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• 2007

This paper investigates summer precipitation change in East Asia according to switching surface boundary condition over South Korea and Shantung. Simulations are carried out by ECHO-G/S for 20 years (1980-1999). Surface condition over both areas in ECHO-G/S is represented by ocean (OCN experiment). In OCN experiment, the summer precipitation is considerably underestimated around the Korean peninsula (the dry region) and overestimated over the eastern Tibetan Plateau (the wet region). It may be related that the lack of the heat sources from the unrealistically prescribed land-sea mask weakens northward expansion of rainband and the development of convective precipitation. Moreover the simulated rainband retreats before June in connection with the early genesis of summer monsoon circulation. The systematic bias of the summer precipitation over the dry and wet regions are reduced comparing with the OCN experiment when the land-sea masks over South Korea and Shantung are realistically considered as land (LND experiment). These improvements can be explained by the thermodynamical dissimilarity between land and ocean. Enhanced warming by switching the areas from sea to land has led to develop the thermal low over Yellow Sea with the cyclonic circulation. Thus, this cyclonic circulation supports moistures from the south to the dry region and blocks to the wet region. The heat transport from the land surface to atmosphere plays a key role in the developing convective precipitation in local scale and maintaining the precipitation and the rainband. Therefore, this results indicate that the design of the realistic land-sea distribution is required for the accurate simulation of the regional precipitation.

• Journal of the korean society of oceanography
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• v.34 no.4
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• pp.185-199
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• 1999

With a realistic geography and topography the Princeton Ocean Model is used to study the effects of topography, wind and time-varying Chanajiang (Yangtze) River discharge on the dispersion of the Chanaiiang River plume in the Yellow and East China Seas. The topographic feature of deepening offshore suppresses the offshore expansion of the discharged low salinity water while spreading along the coast is not hindered. Also the spreading of the Chanajiang River plume is very sensitive to wind conditions and the southerly wind is most responsible for the eastward expansion toward the Cheju Island. It is also shown that the influence of the Chanajiang River Diluted Water on the hydrography and circulation of the Yellow Sea including the South Sea of Korea is substantial even in the absence of tide, wind and current.

• 한국해양학회지
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• v.28 no.2
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• pp.121-131
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• 1993

The tidal front forming in the Mid-Yellow Sea off Korea, near Tae-An peninsular, is calculated using a 3-D general circulation model(Semtner, 1974) and the concept of mixing rate, an extension of the concept of mixing efficiency proposed by simpson & Hunter(1974). Along the north and south open boundaries, simple radiation conditions are applied. The model is run with the initial state which represents the winter condition. With imposed uniform heating by solar radiation and spatially-different vertical mixing, the model then generated the tidal front comparable to the observed one.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.5 no.2
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• pp.151-171
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• 1993

The review presented herein covers most of previous works on tidal models of the East China Sea and the Yellow Sea performed over past two decades including some earlier efforts. General description of tides in the region is given based on both numerically derived tidal charts, current ellipses and intelligently drawn empirical tidal charts. Some aspects of bottom tidal dissipation, tidal mixing, tidal sedimentation and tidal circulation utilizing the numerical tidal models are presented, and further discussions on inherent problems and development of the models are also given.

• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.1
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• pp.29-36
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• 2009

Realtime tide and storm-surge computations for the Yellow Sea were conducted using the Parallel Finite Element Model. For these computations a high resolution grid system was constructed with a minimum node interval of loom in Gyeonggi Bay. In the modeling, eight main tidal constituents were analyzed and their results agreed well with the observed data. The realtime tide computation with the eight main tidal constituents and the storm-surge simulation for Typhoon Sarah(1959) were also conducted using parallel computing system of MPI-based LINUX clusters. The result showed a good performance in simulating Typhoon Sarah and reducing the computation time.

• 한국해양학회지
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• v.22 no.2
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• pp.63-70
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• 1987

Existing oceanographic data indicate that tidal mixing fronts generally prevail in the Eastern Yellow Sea along the Korean coast. In the Western part, these fronts seem to be much weaker. These fronts are believed to be generated mostly by spatially different tidal mixing. The geostrophic adjustment model applied to the observed density structure gives the mixed coastal water flowing northward and the offshore waters(both surface warm and bottom cold waters) flowing southward along the Korean coast. The transport of each water amounts to O(10$\^$4/)m$\^$3//sec.

• Atmosphere
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• v.26 no.3
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• pp.357-372
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• 2016

Northeast Asian regions have recently become the main source of anthropogenic and natural aerosols. Measurement of aerosols on the sea in these regions have been rarely conducted since the experimental campaigns such as ACE-ASIA (Asian Pacific Regional Aerosol Characterization Experiment) in 2001. Research vessel observations of aerosol mass and chemical composition were performed on the Yellow and south sea around the Korean peninsula. The ship measurements showed six representative cases such as aerosol event and non-event cases during the study periods. On non-event cases, the anthropogenic chemical and natural soil composition on the Yellow sea were greater than those on the south sea. On aerosol event cases such as haze, haze with dust, and dust, the measured mass concentrations of anthropogenic chemical and element compositions were clearly changed by the events. In particular, methanesulfonate ($MSA^-$, $CH_3SO_3^-$), a main component of natural oceanic aerosol important for sulfur circulation on Earth, was first observed by the vessel in Korea, and its concentration on the Yellow sea was three times that on the south sea during the study period. Sea salt concentration important to chemical composition on the sea is related to wind speed. Coefficients of determination ($R^2$) between wind speed and sea salt concentration were 0.68 in $PM_{10}$ and 0.82 in $PM_{2.5}$. Maximum wave height was not found to be correlated to the sea salt concentration. When sea-salt comes into contact with pollutants, the total sea-salt mass is reduced, i.e., a loss of $Cl^-$ concentration from NaCl, the main chemical composing sea salt, is estimated by reaction with $HNO_3$(gas) and $H_2SO_4$(gas). The $Cl^-$ concentration loss by $SO_4^{2-}$ and $NO_3^-$ more easily increased for $PM_{10}$ compared to $PM_{2.5}$. The results of this study will be applied to verifying a dust-haze forecasting model. In addition, continued vessel measurements of aerosol data will become important to research for climate change studies in the future.

• 한국해양학회지
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• v.19 no.2
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• pp.187-194
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• 1984

Water masses and circulation in the yellow Sea (Hwanghae) were briefly reviewed and synthesized. Water masses were classified into four types: Hwanghae Cold Water, Hwanghae Warm Current Water, Coastal Waters and Changjiang River Diluted Water. The Hwanghae Cold Water can be defined to have a salinity of 32.0∼33.0% and a temperature below 10$^{\circ}C$, based on long-term hydrographic data and recent CTD casts (KORI, 1984). Concerning circulation, there exists a cyclonic gyre throughout the year in the southern part. In winter, the coastal current along the Chinese coast is very strong due to northerly or northwesterly winds and the Hwanghae Warm Current becomes weak as can be expected from a surface to bottom thermohaline front west of Cheju-do. Meanwhile in summer, the Changjiang River Diluted Water flows northeastward toward Cheju-do and the coastal current in the western part is greatly reduced. The northward current during summer in the southeastern Hwanghae has been accepted to be the Hwanghae Warm Current until now, coastal waters and the Hwanghae Cold Water in the central deep area, not a continuation of the Hwanghae Warm Current.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.6
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• pp.1190-1194
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• 2001

The first 7 years of altimeter data from the TOPEX/POSEIDON(T/P) were analyzed to study the surface circulation and its variability in the East Asian Marginal Seas. Long term averaged T/P sea level time series data where compared with in situ sea level measurements from a float-operated type tide gauge around of south Korea and Japan. T/]P data are a large contaminated by 60-day tidal aliasing effect, very near the alias periods of M2 and 52. When this 60-day effect is removed, the data agree well with the tide gauge data with 4.6 cm averaged RMS difference. The T/P derived sea level variability reveals clearly the well-known, strong current-topography such as Kuroshio. The T/P mean sea level of North Pacific(NP) was higher than Yellow Sea(YS) and East Sea(ES). The T/P sea level variability, with strong eddy and meandering, was the largest in eastern part of Japan and this variability was mainly due to the influence of bottom topography in Kuroshio Extension area.

• Journal of the korean society of oceanography
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• v.39 no.1
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• pp.57-71
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• 2004

Based on the data obtained under the China-Korea joint project (1997-2001) and historic observations, the distribution, transportation and sedimentation of sediment in the southern Yellow Sea (SYS) are discussed, and the controversial formation mechanism of muddy sediments is also explored. The sediment transport trend analysis indicates that the net transport direction of sediment in the central SYS (a fine-grained sediment deposited area) points to $123.4^{\circ}E,\;35.1^{\circ}N$, which is a possible sedimentation center in the central SYS. The sediment transport pattern is verified by the distribution of total suspended matter (TSM) concentration and ${\delta}^{13}C$ values of particulate organic carbon (POC), the latter indicates that the bottom water plays a more important role than the surface water in transporting the terrigenous material to the central deep-water area of the SYS, and the Yellow Sea circulation is an important control factor for the sediment transport pattern in the SYS. The carbon isotope signals of organic matter in sediments indicate that the Shandong subaqueous delta has high sedimentation rate and the deposited sediments originate mainly from the modern Yellow River. The terrigenous sediments in deep-water area of the SYS originate mainly from the old Yellow River and the modern Yellow River, and only a small portion originates from the modern Yangtze River. The analytical results of TSM and stable carbon isotopes are further confirmed by another independent tracer of sediment source, polycyclic aromatic hydrocarbons (PAHs). Five light mineral provinces in the SYS can be identified and they indicate inhomogeneity in sources and sedimentary environment. The modern shelf sedimentary processes in the SYS are controlled by shelf dynamic factors. The muddy depositional systems are produced in the shelf low-energy environments, which are controlled by some meso-scale cyclonic eddies (cold eddies) in the central SYS and the area southwest of the Cheju Island. On the contrary, an anticyclonic muddy depositional system (warm eddy sediment) appears in the southeast of the SYS (the area northwest of the Cheju Island). In this study, we give the cyclonic and anticyclonic eddy sedimentation patterns.